(1)  In this notice, a conjoined trailer unit means a trailer that –

(a) is comprised of two traffic light trailers; and

(b) meets the requirements specified in subclause (2) .

(2)  For the purposes of subclause (1)(b) , the following are specified as the requirements for a conjoined trailer unit:

(a) the traffic light trailers of the unit must be connected in a lead trailer and rear trailer configuration;

(b) the lead trailer and rear trailer must be securely connected to one another by a rigid coupling mechanism so that –

(i) there is no possibility of articulation, or rotation, along the axis of that coupling; and

(ii) when under tow, both trailers move as if they are one single trailer;

(c) both traffic light trailers must be manufactured by the same manufacturer.